Rear Mount Big Block Turbo

Posted By: moparmattkos

Rear Mount Big Block Turbo - 02/22/10 01:51 AM

How many guys have a rear mount turbo? I am wanting to turbo my new indy head big block. I will have a 106mm turbo on it, I was thinking in a rear mount situation to keep the headers to 1 3/4 to keep the pressure up. Any info would be great.

Posted By: joshking440

Re: Rear Mount Big Block Turbo - 02/22/10 01:54 AM

How many cubes?

Posted By: moparmattkos

Re: Rear Mount Big Block Turbo - 02/22/10 03:04 AM

512 low deck

Posted By: joshking440

Re: Rear Mount Big Block Turbo - 02/22/10 03:26 AM

I would use 1 7/8. into dual 2 1/2 the merge right at the turbo. I think that would be the optimum for velocity, which is what you are concerned with on the hot side

Posted By: 72sat

Re: Rear Mount Big Block Turbo - 02/23/10 02:19 AM

since we are just starting this forum,lets start it off right.velocity has nothing to do with boost.its all about volume.not how fast;how much.volume turns a turbo,not air speed.a turbo engineer told me to slap anybody in the head,that talks about velocity,and turbos

Posted By: joshking440

Re: Rear Mount Big Block Turbo - 02/23/10 02:58 AM

Well Im not sure I have met your engineer, but all the guys who build the fastest damn cars on the planet express the necessity for good velocity. I can put a ton of air past a turbine, but if I am only doing it a 1 mph, then how fast is that turbine going to spin

Posted By: moparmattkos

Re: Rear Mount Big Block Turbo - 02/23/10 05:41 AM

Josh what are you using for a fuel pump ? I was told i would need a belt drive pump any ideas?

Posted By: headhunter

Re: Rear Mount Big Block Turbo - 02/23/10 11:36 AM

Quote:

Well Im not sure I have met your engineer, but all the guys who build the fastest damn cars on the planet express the necessity for good velocity. I can put a ton of air past a turbine, but if I am only doing it a 1 mph, then how fast is that turbine going to spin

i aggree i have been told the same thing by every body i have talked to that builds fast turbo cars. i started to go with volume i was doing 2 inch tubes with a 3 inch cross over and wastold it would take a long time to spool the turbo. so now i have 1 3/4 with a 2 1/2 cross over i started to do a 2 inch cross over to spool it instantly

Posted By: joshking440

Re: Rear Mount Big Block Turbo - 02/23/10 12:47 PM

Quote:

Josh what are you using for a fuel pump ? I was told i would need a belt drive pump any ideas?

I am running an aeromotive belt drive. You can run a magnafuel mp4101 if you want to run electric, but if you ahve room belt drive is the way to go because that big pump pulls a lot of juice.

Posted By: joshking440

Re: Rear Mount Big Block Turbo - 02/23/10 12:49 PM

I ran 2" tubes and a 3" crossover, but I have 500" to exhaust to displace, and the next motor will be bigger so I only wanted to build these things once...

Posted By: go green

Re: Rear Mount Big Block Turbo - 02/23/10 06:05 PM

Quote:

since we are just starting this forum,lets start it off right.velocity has nothing to do with boost.its all about volume.not how fast;how much.volume turns a turbo,not air speed.a turbo engineer told me to slap anybody in the head,that talks about velocity,and turbos

Header size is not really anything to loose sleep over. You need exhaust gas volume to spin a turbine.
You change the A/R ratio on the turbine side to suit the amount of volume of exhaust you have to work with.

Example ; Try and blow out a candle with your mouth open wide. Then try with your lips together.

You still have the same amount of volume both ways.

One way has no back preasure the other way does .

This is a silly way of describing it but it works.

You have to meet somewhere in the middle .

Posted By: 105630

Re: Rear Mount Big Block Turbo - 02/23/10 11:24 PM

that was the best EXAMPLE I heard ,bar none go green.

Posted By: 72sat

Re: Rear Mount Big Block Turbo - 02/24/10 03:21 AM

Quote:

Well Im not sure I have met your engineer, but all the guys who build the fastest damn cars on the planet express the necessity for good velocity. I can put a ton of air past a turbine, but if I am only doing it a 1 mph, then how fast is that turbine going to spin

well since we are talking super silly.if you push a ton of air;in a inclosed space vented at the turbo yes its going to spin.because of the volume of air that will be displaced.it can be at 1 mph,but it will still be a ton of air,at a given rate of time(volume)